ASTM A790
Seamless and welded duplex stainless steel pipe
Covers seamless and welded ferritic/austenitic (duplex and super duplex) stainless steel pipe, including 2205 (S31803/S32205), 2507 (S32750) and S32760.
- Pipe & tube
- ASME SA-790
- 3 grades supplied to it
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is ASTM A790?
ASTM A790 is the specification for seamless and welded duplex (ferritic/austenitic) stainless steel pipe for general corrosive service, with particular emphasis on resistance to chloride stress-corrosion cracking. It covers duplex 2205 (S31803, S32205) and super duplex grades such as S32750 and S32760. General requirements are in ASTM A999; tubing is covered separately by ASTM A789. ASME adopts it as SA-790.
ASTM A790 at a glance
| Products | Seamless and straight-seam welded pipe |
|---|---|
| Material family | Duplex and super duplex stainless |
| General requirements | ASTM A999 |
| Heat treatment | Solution annealed and rapidly cooled |
| Temperature | Duplex is normally limited to about 315 °C (600 °F) because of embrittlement at higher temperatures |
| ASME designation | SA-790 |
ASTM A790 grades
Duplex grades are identified by UNS number.
| Grade | UNS | Matching fittings / flanges |
|---|---|---|
| Duplex 2205 | S31803 / S32205 | A815 WPS31803 / WPS32205 · A182 F51 / F60 |
| Super duplex 2507 | S32750 | A815 WPS32750 · A182 F53 |
| Super duplex S32760 | S32760 | A815 WPS32760 · A182 F55 |
ASTM A790 vs A789 vs A928
| Specification | Covers |
|---|---|
| ASTM A790 | Duplex pipe, seamless and welded |
| ASTM A789 | Duplex tubing for general service |
| ASTM A928 | Electric-fusion-welded duplex pipe, usually large diameter |
How to write ASTM A790 on a purchase order
Name the product, size, material specification and grade, the dimensional standard and the certificate. An example line:
Illustrative only — sizes, tests, inspection level and any project values come from your purchase specification.
ASTM A790 edition and verification status
Which edition we have confirmed, and what is still being checked before any numerical requirement is published here.
| Current edition (publisher listing) | A790/A790M-24 — checked 7 October 2026 |
|---|---|
| Full-text verification | In progress — numerical requirements are published here only after the current text has been reviewed |
| Edition on your order | The edition named in your purchase order or design code governs — confirm it with your enquiry |
What to know before ordering to ASTM A790
The points that decide whether material to ASTM A790 is accepted at inspection.
- Heat treatment and quench requirements matter for duplex; the certificate should state them.
- Tubing in the same grades is ordered to ASTM A789 instead.
- Ferrite content and impact testing are often added by oil-and-gas client specifications.
Grades and products we supply to ASTM A790
| Grade | Product | Designation on the certificate |
|---|---|---|
| Duplex 2205 | Pipe & Tube | ASTM A790 |
| Duplex 2205 | Pipe & Tube | ASTM A790 · A928 |
| Super Duplex 2507 | Pipe & Tube | ASTM A790 |
| Super Duplex 2507 | Pipe & Tube | ASTM A790 · A928 |
| Super Duplex S32760 | Pipe & Tube | ASTM A790 |
| Super Duplex S32760 | Pipe & Tube | ASTM A790 · A928 |
How ASTM A790 fits into an order
A purchase order line is only complete when it names the material standard, the dimensional standard and the inspection document. Miss one and the mill, the inspector and the buyer can each read the order differently.
Standards used with ASTM A790
Same family
ASTM A790 — questions buyers ask
What is ASTM A790?
ASTM A790 is the specification for seamless and welded duplex (ferritic/austenitic) stainless steel pipe for general corrosive service, with particular emphasis on resistance to chloride stress-corrosion cracking. It covers duplex 2205 (S31803, S32205) and super duplex grades such as S32750 and S32760. General requirements are in ASTM A999; tubing is covered separately by ASTM A789. ASME adopts it as SA-790.
What is the difference between ASTM A790 and A789?
A790 covers pipe (ordered by NPS and schedule); A789 covers tubing (ordered by outside diameter and wall).
What is the difference between S31803 and S32205?
S32205 has tighter, higher minimums for chromium, molybdenum and nitrogen, giving better pitting resistance. Most 2205 is dual-certified to both.
Can duplex pipe be used at high temperature?
Generally not above about 315 °C (600 °F); longer exposure in the 300–500 °C range causes embrittlement. Use austenitic or nickel alloys for hot service.
Which grades do you supply to ASTM A790?
Duplex 2205, Super Duplex 2507, Super Duplex S32760 — see the table on this page for the exact product and designation.
What is the current edition of ASTM A790?
The publisher's listing checked on 7 October 2026 shows A790/A790M-24 as the current edition. The edition that governs an order is the one named in the purchase order or design code. Full-text review of the current edition is in progress, so numerical requirements are not published on this page yet.
Do you supply certificates to this standard?
Yes. Material is supplied with mill test certificates to EN 10204 3.1 showing the standard, grade and heat number; 3.2 with third-party inspection on request.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026